The present invention is directed to plasticized thermotropic liquid crystalline polymers and to toner compositions for developing electrostatic latent images. More specifically, the present invention is directed to thermotropic liquid crystalline polymers containing plasticizer or antiplasticizer additives and to toner compositions containing liquid crystalline polymers modified with plasticizers or antiplasticizers. One embodiment of the present invention is directed to a composition comprising a thermotropic liquid crystalline resin and a modifying component selected from the group consisting of plasticizing agents, antiplasticizing agents, small nonpolymeric liquid crystalline molecules, and mixtures thereof. Another embodiment of the present invention is directed to a toner composition comprising a thermotropic liquid crystalline resin, a colorant, and a modifying component selected from the group consisting of plasticizing agents, antiplasticizing agents, small molecule liquid crystalline materials, and mixtures thereof.
Toner compositions containing liquid crystalline materials are known. For example, U.S. Pat. No. 4,543,313 (Mahabadi et al.), the disclosure of which is totally incorporated herein by reference, discloses toner compositions comprising resin particles selected from the group consisting of thermotropic liquid crystalline polycarbonates, copolycarbonates, polyurethanes, polyesters, and copolyesters, and pigment particles.
U.S. Pat. No. 4,891,293 (Sacripante et al.), the disclosure of which is totally incorporated herein by reference, discloses thermotropic liquid crystalline polymers of specific formulae, and toner and developer compositions containing these polymers.
U.S. Pat. No. 4,973,539 (Sacripante et al.), the disclosure of which is totally incorporated herein by reference, discloses a toner composition comprising a crosslinked thermotropic liquid crystalline polymer, a branched liquid crystalline polymer, or mixtures thereof.
U.S. Pat. No. 5,030,533 (Bluhm et al.), the disclosure of which is totally incorporated herein by reference, discloses a photoresponsive imaging member comprising a photogenerating layer and a charge transport layer comprising hole transport molecules dispersed in a resin binder mixture wherein at least one of the resins is a liquid crystalline thermotropic polymer.
U.S. Pat. No. 3,655,256 (Claytor et al.) discloses methods and apparatus for reproducing optical information in thermochromic materials. Exemplary materials are the ternary halides, ternary chalcogenides, and certain transition metal oxides. Methods and apparatus are also disclosed for recording holographic images with infrared radiation and reconstruction infrared holograms in the visible portion of the spectrum.
U.S. Pat. No. 3,655,270 (Creagh) discloses a display device wherein a layer of a novel nematic mesomorphic composition that is normally transparent to light scatters light in response to a voltage applied across the composition. The composition consists essentially of a ternary mixture of 4-ethoxybenzylidene-4'-n-butylaniline, 4-methoxybenzylidene-4'-amino-phenyl butyrate, and bis-(4'-n-octyloxybenzal)-2-chloro-1,4-phenylene-diamine, and exhibits the nematic mesophase over a broad temperature range that includes room temperature.
U.S. Pat. No. 3,873,181 (Chivian et al.) discloses methods and apparatus for recording and reproducing optical information in thermochromic materials. Exemplary materials are the ternary halides, ternary chalcogenides, and certain transition metal oxides. Also disclosed are optical data processing apparatus using long wavelength radiation, and devices utilizing techniques for quality control or semiconductor device fabrication. Relatively compact optical correlators using infrared radiation and adapted to sort mail are also disclosed.
U.S. Pat. No. 4,615,962 (Garito) discloses dialkenyl diacetylenes, especially divinyl diacetylenes having liquid crystalline phases. The diacetylenes having liquid crystalline phases may be polymerized while in the liquid crystalline state to yield onjugated polymers. The processes for the polymerization of the liquid crystalline diacetylenes and for the elaboration of useful optical, electro-optical, electro-acoustic, mechanical, thermal, structural, waveguiding, and other articles are also disclosed.
U.S. Pat. No. 4,780,383 (Garrett et al.) discloses a process for optical storage which utilizes a photopolymerizable liquid crystalline material having cholesteric optical properties. By selectively adjusting the reflectance or transmittance properties of the recording medium such that specific wavelength bands of light are reflected or transmitted, and then substantially permanently fixing the reflectance or transmittance characteristics of the film by photopolymerization, multiple wavelength-dependent information can be stored in each dot. Accordingly, the capacity of the recording medium is substantially expanded when compared to conventional optical storage media.
U.S. Pat. No. 4,818,070 (Gunjima et al.) discloses a liquid crystal optical device comprising a pair of substrates provided with electrodes and a layer containing a liquid crystal material sandwiched between the pair of substrates, wherein the layer is formed by irradiating light to a mixture of a liquid crystal material and a photocurable compound selected so that the refractive index of the resulting cured product agrees to either the ordinary refractive index or the extraordinary refractive index of the liquid crystal material used, or the refractive index of the liquid material when it is randomly oriented, held between the pair of substrates provided with electrodes, to cure the photocurable compound and fix the resulting phase separation of the liquid crystal material and the cured product, wherein the layer has at least a portion optically oriented by applying a voltage to the portion across the substrates during the irradiation of light to cure the photocurable compound.
U.S. Pat. No. 4,929,658 (Kotoh et al.) discloses a composition to be used as an agent for aligning liquid crystals in a liquid crystal cell, wherein liquid crystal molecules are aligned with an increased pretilt angle with respect to the substrate, the composition consisting essentially of a polyimide resin precursor and a precursor of a diimide compound.
U.S. Pat. No. 4,959,252 (Bonnebat et al.) discloses rigid, dimensionally stable, essentially circular and planar, axially injection molded disc members, well adapted as support substrates for radiation sensitive layers for optical discs such as laser discs which comprise radially molecularly oriented thermotropic polymers. The disc members have a radiation sensitive microrelief pattern on at least one of the face surfaces thereof.
"Structural Studies of Liquid-Crystalline Poly(ester amides)," N. S. Murthy et al., Macromolecules, vol. 25, pages 1177 to 1183 (1992), is directed to a study of the structure of a series of poly(ester amides) by small- and wide-angle X-ray diffraction. Diffuse and weak small-angle X-ray reflections with spacings longer than the chain-axis repeat are reported to be present when the polymer is in the quenched smectic phase, and they become sharp and intense as the crystalline order increases in the presence of a DMF solvent.
Although known compositions and processes are suitable for their intended purposes, a need remains for means for adjusting the glass transition temperatures of thermotropic liquid crystalline polymers. A need also remains for improved toner compositions. In addition, a need remains for improved toner compositions containing liquid crystalline resins and having all the advantages provided thereby. Further, a need remains for toner compositions containing liquid crystalline resins for which the glass transition temperature can be adjusted. Additionally, there is a need for toner compositions containing liquid crystalline resins for which the glass transition temperature is optimized so that the energy required to fuse the toner is minimized. There is also a need for toner compositions containing liquid crystalline resins for which the glass transition temperature is optimized so that blocking (i.e., agglomeration of toner partices under machine dormant conditions) and offset (i.e., transfer of toner from the original receiver sheet, such as paper or transparency material, to other surfaces, such as notebook covers, adjacent receiver sheets in a stack, or the like) is minimized or eliminated.